Programmable CPU Power Supply Unit

EL7556AC EL7556AC Programmable CPU Power Supply Unit Features • EL7556C Pin Compatible • Improved Temperature and Voltage Ranges • 6A Continuous Load Current • Precision Internal 1% Reference • 1.0V to 3.8V Output Voltage • Internal Power MOSFETs • >90% Efficiency • Synchronous Switching • Adjustable Slope Compensation • Over Temperature Indicator • Pulse by Pulse Current Limiting • Operates up to 1MHz • 1.5% Typical Output Accuracy • Adjustable Oscillator w/Sync • Remote Enable/Disable • Intel P54 and P55 Compatible • VCC2DET Interface www.DataSheet4U.com • Internal Soft Start General Description The EL7556AC is an adjustable synchronous DC:DC switching regulator optimized for a 5V input and 1.0-3.8V output. By combining integrated NMOS power FETS with a fused-lead package the EL7556AC can supply up to 6A continuous output current without the use of external power devices or discrete heat sinks, thereby minimizing design effort and overall system cost. On chip resistorless current sensing is used to achieve stable, highly efficient, current-mode control. The EL7556AC also incorporates the VCC2DET function to directly interface with the Intel P54 and P55 microprocessors. Depending on the state of VCC2DET the output voltage is internally preset to 3.50V or a user adjustable voltage using two external resistors. In both internal and external feedback modes the active-high PWRGD output indicates when the regulator output is within ±10% of the programmed voltage. An on-board sensor monitors die temperature (OT) for over-temperature conditions and can be connected directly to OUTEN to provide automatic thermal shutdown. Adjustable oscillator frequency and slope compensation allow added flexibility in overall system design. Applications • • • • • • PC Motherboards Local high power CPU supplies 5V to 1.0V DC-DC Conversion Portable Electronics/Instruments P54 and P55 Regulators GTL+ Bus Power Supply Connection Diagram R4 R3 100Ω 150Ω VIN D3 1 C4 0.1µF 2 C7 150pF 3 C8 R5 220pF 4 5 5Ω 6 FB1 CREF CSLOPE COSC VDD VIN VSSP VIN VSSP FB2 28 C5 CP 27 R1 C2V 26 68Ω VSS 25 R6 VHI 24 C6 LX 23 0.1µF LX 22 LX 21 LX 20 VSSP 19 VSSP 18 TEST 17 L1 2.5µH C10 1mF 68Ω D1 0.22µF C11 1µF D2 D4 Ordering Information Part No Temp. Range Package 28-Lead SOIC Outline # MDP0027 EL7556ACM -40°C to +85°C VIN 7 C9 660µF C3 C12 0.1µF 8 9 VOUT 10 VSSP 1µF 11 VSSP 12 VSSP Connect to VSSP for external feedback 13 VCC2DET 16 PWRGD February 28, 2000 14 OUTEN OT 15 C3, C4, C5, C6, C7 C8 - ceramic C5, C11 - ceramic or tantalum C9 - Sprague 594D337X10010R2T 2X330µF C10 - Sprague 594D337X10010R2T 3X330µF L1 - Pulse Engineering, PE-53681 D1-D4: BAT54S fast diode EL7556AC Manufactured under U.S. Patents No. 5,723,974 and No. 5,793,126 Note: All information contained in this data sheet has been carefully checked and is believed to be accurate as of the date of publication; however, this data sheet cannot be a “controlled document”. Current revisions, if any, to these specifications are maintained at the factory and are available upon your request. We recommend checking the revision level before finalization of your design documentation. © 2000 Elantec, Inc. EL7556AC EL7556AC Programmable CPU Power Supply Unit Absolute Maximum Ratings (T Storage Temperature Range Supply (V ) IN Ambient Operating Temperature A = 25 °C) -65°C to +150°C 6.0V -40°C to +85°C Output Pins Operating Junction Temperature Peak Output Current -0.3V below GND, +0.3V above VDD 135°C 9A Important Note: All parameters having Min/Max specifications are guaranteed. Typ values are for information purposes only. Unless otherwise noted, all tests are at the specified temperature and are pulsed tests, therefore: TJ = TC = TA. Electrical Characteristics VDD = VIN = 5V, COSC = 1nF, CSLOPE=470pF, TA=25°C unless otherwise specified. Parameter General IDD IDDOFF IVIN VOUT1 VOUT2 VOUTLINE VOUTLOAD RSHORT II MAX VOUTTC TOT THYS VPWRGD VDDOFF VDDON VHYS M SS Description VDD Supply Current VDD Standby Current VIN No Load Current Output Initial Accuracy Output Initial Accuracy Output line Regulation Output Load Regulation Short Circuit Load Resistance Current Limit Output Tempco Over Temperature Threshold Over Temperature Hysteresis Power Good Threshold Relative to Programmed Output Voltage Minimum VDD for Shutdown Maximum VDD for Startup Input Hysteresis Soft start slope Maximum duty cycle VCC2DET, OUTEN Pull Up Current Cslope Charging Current FB1 Input Pull Up Current Over Temperature Pull Up Resistance VCC2DET, OUTEN Input High VCC2DET, OUTEN Input Low Powergood Drive High Powergood Drive Low Reference Accuracy Reference Voltage Tempco Reference Load Regulation ILoad=1mA ILoad=-1mA IREF=0 OT=0V -40°C